Let's not forget the original topic of this post way back when I posted it which was finding a way to make using PW themes easier than WP.
With WP most people who don't know how to use a lot of PHP end up buying a theme as is or maybe buying a theme and re-skinning it directly (via css etc.) or even using a child theme. And we all know there are a bazzillion themes out there to choose from. Allot of them with built in admin panels for changing almost everything in a design from colors to fonts to logos etc. Then little by little when they out grow re-skinning and feel more comfortable with things they start playing with PHP and WP's "loop" among other things.
Bringing up template engines was only one idea to help make things easier for people though, I'm sure there are many other ideas as well. With that said, it's probably a much bigger issue than just using a template engine or not.
PW, as it sits now anyway, isn't really setup for themes as much as it is for building sites from scratch. This is similar to other systems, like EE for example, as you can't install themes over themes per se. I think that's the case with PW as well though, I could be wrong so, please correct me if I am.
The flexibility, power and freedom CMS like this provide takes work to use & to learn and often times when you are just starting out its just easier to, well, not work/learn.
Anyway, maybe that was why the post was started in the first place, I don't know. For me, offering a template engine is kind of a mid ground in a sense, as it allows people with less php experience to "feel" more comfortable. I do get the arguments about having to learn one thing so, might as well learn PHP from the start, however, that doesn't address the issue at hand (or at least the original topic from the quote.)
By the way, there are also other reasons which no one has mentioned which make using a template engine a possible good option like separation between logic and view (or what ever it's called.) Allot of other languages, frameworks actually, offer this pretty much by default (although by choice.) Not saying PW needs to do that rather, I'm just saying.
Ultimately, I guess we never really answered the question from the quote above and I'm curious (as I don't know myself) how to make working with and installing PW themes as easy (easier) than WP?
(and let's not forget about one click upgrades for both core and modules!)